Excess weight and obesity now affect all populations, both in developed and developing countries. They are the cause of chronic diseases, such as, for the most part, cardiometabolic diseases, particularly diabetes and cardiovascular diseases, as well as certain cancers, neurodegenerative diseases and inflammatory bowel diseases, affecting a large part of the world's population and becoming the leading cause of death.
Modern medicament is helpless in the face of these chronic pathologies, whose management is more difficult, more time-consuming and less dichotomous than acute diseases. In addition, the durability of these diseases over time, with the aging of the population, has a considerable impact on public health spending, which is becoming unbearable.
Therefore, a first objective of the invention is to propose a simple, effective and economical solution for dealing with this major health problem.
The pandemic of these chronic diseases seems to be linked to a combination of several factors: a “western diet,” physical inactivity and genetic and epigenetic factors.
The research to combat these pathologies initially focused on food intake imbalances, both quantitative and qualitative (in particular a high consumption of saturated lipids, fructose and carbohydrates), associated or not with a sedentary lifestyle, which lead to weight gain. However, it was found that everyone is not equal before the same food intake and research has been conducted to assess the impact of genetics and epigenetics on weight gain. This research has shown that only a very small fraction of the problems of excess weight and obesity were attributed in a direct way to genetics. On the other hand, epigenetic results have revealed an interest in the microbiome, which seems to play an important role in many chronic diseases, particularly obesity and cardiometabolic diseases. In particular, it has been found that quantitative dysbiosis but above all functional intestinal dysbiosis can lead to an increase in the absorption and storage of energy in the form of fat, with an equal amount of food intake. This functional dysbiosis is due to the disappearance or marginalization of certain bacteria that have a positive influence on the health of the host. Most of these bacteria are inheritable; this explains the existence of bloodlines of skinny or fat individuals, or the existence of obese individuals who never have metabolic disorders, particularly in the blood glucose and lipids, because they do not have functional intestinal dysbiosis due to the fact that the genes of the host do not undergo mutation.
Indeed, if the existence of a microbiome/brain interaction was the first step in understanding the action of the microbiome, particularly in the context of excess weight through receptors of satiety in particular, the most important discovery was the one of the heritability of bacteria. This notion of heritability was demonstrated by the study of cohorts of monozygotic twins (Goodrich “Genetic determinant of the gut microbiome in UK twins,” CellPress 2016), and gave an explanation for the transmission of obesity or of certain chronic diseases. Thus, in the context of obesity and cardiovascular diseases, it was discovered that gene variations were directly related to the visceral fat, explaining the epidemics of obesity and metabolic syndrome, in particular diabetes and cardiovascular diseases, a fact that is true in both developed countries and emerging countries such as China and South American countries. This new notion of epigenetics has revolutionized the understanding of many chronic diseases and allows considering new treatments thanks to the bacteria that can compensate genetic changes. This is all the more important as it is now proven that the epigenetics of mother and father can be transmitted to children, especially in obesity. Another object of the invention is therefore to propose a solution for controlling, in particular, excess weight, obesity, cardiometabolic diseases and inflammatory bowel diseases by acting on the intestinal microbiome and, in particular, on inheritable bacteria. The microbiome is a set of microorganisms (bacteria, archaea, viruses and eukaryotes grouped into domains) that are specific to each individual. These microorganisms are found on the skin, in the mouth and in the largest number in the digestive system, which has about 3.3 million of them. This microbiome thus contains a number of genes one hundred and fifty times greater than that of the human genome.
The different classification levels of the bacteria are: domain, phylum, class, order, family, genus, species and strain. The bacteria are also identifiable and can be characterized by OTUs (Operational Taxonomic Units), an OTU corresponding to a grouping of bacteria strains of the same species whose 16S rRNA sequences have a similarity of over 97%.
Several methods currently exist to know and analyze the bacteria constituting the intestinal microbiome:                cultivation: this technique is limited because 80% of the microbiome is not cultivated (currently, only one thousand species are cultivated because of difficulties in practicing this cultivation);        biological marking using 16S rRNA as a marker;        sequencing of OTU either by the Sanger method or by pyrosequencing of the 16S rRNA;        imprint by electrophoresis, polymorphism and ribosomal;        DNA chips;        the FISH and qPCR methods with amplification of a group;        shotgun metagenomic analysis;        meta-analysis with metagenomics (composition and function of all genes), metaproteomics (protein analysis), metabolomics (metabolic profile) and metatranscriptomics (RNA).        
However, currently, among the millions of bacteria constituting the microbiome, very few (about one thousand) are defined, characterized and cultivated.
Each individual has his own microbiome that comes from his history and his roots, but there are species common to many individuals. In particular, it is known that over 85% of the species are common between Europe, the United States and Japan.
Moreover, the intestinal microbiome is not homogeneous. It varies in quantity and quality when it comes to the stomach, the duodenum, the jejunum, the ileum and finally the colon, where there is the greatest number of anaerobic bacteria. It is also known that certain bacteria are found in the mucus that lines the intestinal wall.
In addition, the immune system, the genetic system and the neurotransmitters (particularly those linking the intestine and the brain) influence the microbiome, making its study even more complex.
It is therefore a particularly delicate domain because of its complexity and the number of inter-reacting factors and it is impossible today to establish a standard microbiome of good health.
We know that the diversity as well as the richness of the microbiome decreases in case of excess weight and obesity (61% of obese individuals have a low number of genera). Research has been conducted on the correlation between certain phyla (including firmicutes, bacteriodetes, proteobacteria and actinobacteria) and excess weight and/or obesity. A relationship in the firmicutes-bacteriodetes ratio has been described as increasing with body mass index (BMI), but with the replication of studies, some scientists have reversed this judgment by demonstrating the opposite. Thus, staying at the level of large groups such as phyla does not provide a solution to combat excess weight and/or obesity and/or chronic metabolic diseases. Research has focused on lower levels of bacterial classification, at the level of families, genera, species and even strains.
Numerous studies have been carried out in the families of bacteria, but, here again, no satisfactory results have been obtained. Indeed, a family can contain dozens of species and even more strains, without the possibility of knowing which bacterium or bacteria is active. In addition, some families may harbor hazardous species alongside beneficial species.
Recent studies have been carried out on species likely to influence weight loss by their increase in the microbiome, namely Akkermansia muciniphila, Methanobrevibacter smithii, Faecalibacterium prausnitzii, Bifidobacterium longum, Roseburia intestinalis, Eubacterium rectale and Christensenella minuta. However, the studies were carried out only on the mouse, which does not suggest any activity on humans. Mouse studies are unreliable because these animals have a different microbiome from humans and mice with humanized microbiome lose their natural reactions on metabolic markers.
As to cardiometabolic diseases such as diabetes, it has been shown that there may be a significant decline in Clostridiales and an increase in Bacteriodetes in vitro or in animals, as well as a decrease in Roseburia intestinalis and Faecalibacterium pransnitzii, which are thought to regulate glucose and blood sugar through the permeability of the intestinal barrier, but, here again, these findings do not allow a satisfactory solution to fight against excess weight, obesity and the resulting cardiometabolic diseases because of the excessive number of different bacteria.
Three types of bacterial therapies acting on the microbiome have been proposed to date. The first was to use prebiotics to increase all of the bacteria in order to compensate for the decrease induced by obesity. However, this solution is at best a lure and at worst a danger by increasing the unwanted bacteria which is the natural tendency of the microbiome in dysbiosis. Selective growth was also investigated in vitro by crossing selected food on selected strain but this did not work in humans.
The second consisted in using probiotics as “food” for the development of selected bacteria. This solution is not satisfactory either because the developed probiotics have been limited to the food bacteria which are used in the first part of the intestine, whereas the metabolically interesting bacteria are in the colon and nested in the mucus. Moreover, it is difficult to demonstrate an action on humans in the long term because their activity is highly random. Finally, the third solution proposed is the fecal implantation of bacteria of normal or lean individuals to obese people using a technique that works on mice. This technique has the disadvantage of trying to implant foreign strains which can be rejected and there is a possible transmission of carcinogenic signals according to the fears expressed by oncologists. There is therefore no therapeutic solution acting on the microbiome that is satisfactory for humans who are overweight, obese and/or suffer from cardiometabolic diseases and/or inflammatory bowel diseases.